Fig. 1. Mid-shaft cross-sectional shape of the humeri and femurs of greyhounds and pit bulls. (A) Comparison of representative mid-shaft cross sections of the humeri and femurs from a greyhound and a pit bull. In both cases, the greyhound bone is on the left. The anterior-posterior axis is oriented vertically, with anterior at the top. (B) Mean ± S.E.M. of circularity index (CI) for the mid-shaft cross sections of the humeri and femurs of four greyhounds and four pit bulls. The CI is 1 for a circular cross section and is <1 for noncircular cross sections.